Protesters rally against plans to pass the Dakota Access pipeline near the Standing Rock Sioux reservation in North Dakota in November. (Stephanie Keith/Reuters)

The deputy secretary of the Army will grant the final permit needed to complete the Dakota Access Pipeline, the Army declared in a court filing Tuesday, clearing the massive infrastructure project’s last bureaucratic hurdle.

The Army’s intention to grant a 30-year easement under North Dakota’s Lake Oahe was immediately hailed by congressional Republicans and decried by members of the Standing Rock Sioux tribe and other opponents.

In documents filed with the U.S. District Court for the District of Columbia, as part of an ongoing federal environmental review of the controversial pipeline, Army officials indicated that they were terminating a plan to prepare an environmental-impact statement on how the pipeline would affect land and water along its 1,170-mile route.

The move, coming two weeks after President Trump instructed the Army Corps of Engineers to conduct an expedited review of the easement, underscores the new administration’s intent to spur infrastructure development and support the fossil fuel industry. Both during the presidential campaign and since taking office, Trump has spoken of the need to accelerate domestic energy production and the construction of pipelines that can bring oil and gas to market.

While couched in dry language — a letter from Deputy Assistant Secretary of the Army Paul D. Cramer to Rep. Raúl M. Grijalva (D-Ariz.) details the 7.37 acres the pipeline would cross on federal property — the decision marks a major blow to activists who had come from across the country last year and gathered on the Standing Rock’s windswept reservation. There, they declared, a tribe and its allies would defy the federal government.

The project would cross four states and carry crude oil from the rich shale oil basins of western North Dakota to the pipeline networks and refineries in the Midwest. Opponents argue that it could damage the environment and disturb ancient burial grounds.

Construction cannot begin until the easement is granted, which Cramer wrote will be given to the project’s sponsor Energy Transfer Partners no later than Wednesday afternoon. The company declined to comment Tuesday.

The section of the project running underneath Lake Oahe is one of the final parts to be built, and it could be operational between 60 and 80 days after construction starts.

In the wake of the Army’s decision, confrontations at the site could flare anew between activists and law enforcement. While tribal leaders have urged their supporters to go home as the weather worsens, a few hundred protesters have remained. Last week, authorities arrested 74 activists who had decamped from the tribal reservation to land owned by Energy Transfer Partners.

Fights over pipeline siting have become a new front in the broader push to address climate change, with environmentalists arguing that curbing pipelines will limit the amount of carbon released into the atmosphere by restricting the extent to which fossil fuels can be extracted and burned. At the same time, projects such as Dakota Access have reignited the sense of injury among many American Indians, who believe that the land in question belongs to them under treaties they signed with the federal government in the 1800s.

“We are a sovereign nation and we will fight to protect our water and sacred places from the brazen private interests trying to push this pipeline through to benefit a few wealthy Americans with financial ties to the Trump administration,” Standing Rock Chairman Dave Archambault II said in a statement Tuesday. “Americans have come together in support of the Tribe asking for a fair, balanced and lawful pipeline process. The environmental impact statement was wrongfully terminated. This pipeline was unfairly rerouted across our treaty lands. The Trump administration — yet again — is poised to set a precedent that defies the law and the will of Americans and our allies around the world.”

The tribe said Tuesday that it plans to challenge the easement decision. Officials have asked a court to compel Energy Transfer Partners to publicly disclose its oil spill and risk assessment records for the project. Ultimately, the tribe said, it will seek to shut down the pipeline’s operations if it is constructed.

Keith Benes, a former State Department lawyer who helped oversee pipeline permitting decisions under the Obama administration and now works as an environmental consultant, said in an interview that opponents could mount a strong legal challenge because the only justification the Army gave for terminating its environmental review was the president’s Jan. 24 directive. The agency had been seeking public input on whether to consider an alternate pipeline route, and the comment period was due to close Feb. 20.

“Supreme Court precedent is really clear that agencies can change their minds about policies, but they need to provide a reason,” Benes said, noting that the justices most recently upheld this position in the 2009 case FCC v. Fox Television Stations, Inc. “The president telling you to change your mind is not enough of a justification for changing your factual finding.”

Jan Hasselman, a lawyer with the environmental group Earthjustice, said the new administration had no right to short-circuit a process started by then-Obama administration officials to scrutinize the project’s potential impact on critical resources along the route. Late last year, after weeks of protest, then-President Barack Obama instructed the Army corps to look at different route options for the pipeline.

“The Obama administration correctly found that the Tribe’s treaty rights needed to be respected, and that the easement should not be granted without further review and consideration of alternative crossing locations,” Hasselman said in an email. “Trump’s reversal of that decision continues a historic pattern of broken promises to Indian Tribes and violation of Treaty rights. They will be held accountable in court.”

Backers of the pipeline, who argue that it is the most effective means of transporting crude oil extracted on the Great Plains, hailed the Army’s decision.

“New energy infrastructure, like the Dakota Access Pipeline, is being built with the latest safeguards and technology,” Sen. John Hoeven (R-N.D.) said in a statement. “The discord we have seen regarding the Dakota Access Pipeline doesn’t serve the tribe, the company, the corps or any of the other stakeholders involved. Now, we all need to work together to ensure people and communities rebuild trust and peacefully resolve their differences.”

And Craig Stevens, a spokesman for the business-backed MAIN coalition, called the action “proof-positive of President Trump’s commitment to supporting domestic energy development, including midstream infrastructure projects. Today’s action sends a strong positive signal to those individuals and companies seeking to invest in the U.S. and will help strengthen our economy and create jobs.”

A Native Nations march on Washington has been planned for March 10, with the Standing Rock Sioux and others across the country expected to join protesters in demonstrating against the pipeline project.

“Expect mass resistance far beyond what Trump has seen so far,” Tom Goldtooth, executive director of the Indigenous Environmental Network, said in a statement.